(transitive) To strike or bump (someone or something) out. / (transitive, idiomatic) To render unconscious, as by a blow to the head. / (transitive, idiomatic) To put to sleep.

(transitive, idiomatic) To astonish; to stagger or overwhelm; to confuse or disorient.

(Britain) A secondary, often unintended effect; a repercussion, chain reaction.

(idiomatic, US) To take a customary action to ward off some misfortune that is believed to be attracted by a presumptuous statement.

(idiomatic, US) Hopefully; a self-directive to undertake the customary action to ward off bad luck.

(idiomatic) To assemble something quickly; to knock up.

simple past tense and past participle of knock up

(slang, sometimes offensive) Pregnant, typically outside of marriage. / (slang, archaic) Exhausted; worn out or used up.

Alternative spelling of knock knee

(of the legs) having the knees abnormally close together, and the ankles spread apart / (of a person or animal) suffering from genu valgum (or tibia valga)